Bladder cancer is a tumor most commonly found in urinary systems. Although numerous steps were adopted for the treatment, 40-70% of the patients relapsed once or more than once and 10-15% of the patients developed more severe tumors or involved metastasis. Moreover, all these treating processes have apparent toxic and side-effects.
One important clinical task is to prevent relapse of bladder cancer after excision of tumors. Currently, the medicaments used for preventing relapse by bladder perfusion are mainly divided into the following several classes: (1) anti-tumor chemotherapeutic agents, such as Mitomycin C, etc.; (2) immunopotentiators, such as Bacillus Calmette-Guerin Vaccine (BCG), etc.; and (3) cytokines, such as interferon, etc. Although the above classes of medicaments, used either alone or in combination, achieved some effects in the reduction of the relapse rate after the operation of bladder cancer, the overall therapeutical effect is not desirable due to the presence of many issues such as low specificity, multiple drug resistance (MDR) of tumors, and so on. Moreover, because of their low molecular weights, the above classes of medicaments not only can act on the entire bladder and urethra unspecifically, but also can be absorbed by the mucous membranes of bladder and urethra, which easily results in topical or systematic toxic and side-effects. For instance, in the case of Mitomycin C and Bacillus Calmette-Guerin Vaccine which have more positive therapeutical effects, 90% of the patients who had received Bacillus Calmette-Guerin Vaccine were suffered from BCG cystitis and other side effects including hematuria, tetter, fever, arthritis, urethral stricture and the like, or infrequently, even some severe conditions, such as hepatitis, pneumonia, life-threatened septicemia and so on. Mitomycin C has fewer side effects, however still 5-25% of the patients who had received Mitomycin C were suffered from chemical cystitis and anaphylaxis, and other side effects included urethral stricture, marrow depression, calcification of bladder wall, and so on.
Integrin is a group of divalent cation-dependent cell surface receptors with a major function of mediating cell-matrix, cell-cell adhesion by binding to corresponding ligands, so as to further affect cell shapes, gene expression and regulation, cell proliferation and differentiation, apoptosis, and migration, infiltration and metastasis of tumor cells, etc. Integrin is composed of non-covalent subunits α and β. Various combinations result in different ligand-binding abilities. Integrin subunit α3 (CD49c) can be combined with subunit β1 (CD29) to form integrin α3β1. The ligands for integrin α3β1 are laminin (LN) and Collagen IV. In epithelial tissues, integrin α3β1 is mainly involved in the conglutination between cells and basilar membranes of epithelial cells and can adjust signal transduction, thereby impacting the biological features of cells. Integrin α3β1 is modified aberrantly on the surface of tumor cells, which is considered to cause a change in malignancy.
Anti-tumor targeted drugs are biological or chemical molecules (e.g. monoclonal antibodies) with an ability to recognize and kill tumor cells specifically. Bladder cancer is a tumor inside the body cavity of human, i.e. a “somatic test tube” of human body. Targeted drugs have high specificities with and strong lethal effects on target cells in vitro. Therefore, in terms of the treatment for bladder cancer, it is very important to find a novel targeted drug directed against bladder cancer in human.
In screening for bladder tumors, early detection and accurate prognosis of bladder cancer appear to be extremely critical for clinical treatment. For the past several years, the molecular markers, such as nuclear matrix protein, bladder tumor antigen and satellite instability etc. newly involved in clinic were also limited by their low sensitivities and specificities. Urine cytological analysis and cystoscopy are still the golden criteria for the diagnosis and monitoring of bladder cancer. Therefore, it is extremely necessary to find an effective and convenient process for diagnosing bladder cancer.